Effects of environmental factors on the oxidative status of Anemonia viridis in aquaculture systems

Due to its depletion in natural settings, the potential for aquaculture of the cnidarian Anemonia viridis is currently attracting research interest. Knowledge about the physiology of this species is necessary to ensure optimal development of, and well-being in, aquaculture. This study tested the effects of different abiotic (limited sunlight, brackish water) and biotic (integrated multitrophic aquaculture or IMTA) conditions on A. viridis in captivity. Growth and reproduction were measured, and antioxidant status was evaluated in tentacular and columnar tissues as antioxidant enzymatic activity (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose 6-phosphate dehydrogenase, glutathione S-transferase and DT-diaphorase), Trolox-equivalent antioxidant capacity (TEAC) and tissue lipid peroxidation (MDA). Animals in the brackish water and IMTA treatments displayed significant changes in glutathione peroxidase, glucose 6-phospate dehydrogenase and TEAC compared to control anemones, with these effects noted primarily in columnar tissue. These results support the relevance of enzymatic pathways involving glutathione as antioxidant mechanisms under osmotic disturbances or ecological interactions. Limited light intensity was not found to be detrimental to the oxidative status of the anemones, despite A. viridis harbouring photosynthetic symbionts, and enhanced growth performance parameters suggested a higher individual weight increase than in control conditions. Lipid peroxidation was not significantly affected in any experimental condition. Principal Component Analysis (PCA) suggested that similar antioxidant status parameters can correlate positively (tentacular parameters) or negatively (columnar parameters) with MDA concentration. In conclusion, aquaculture of Anemonia viridis can be improved under suitable environmental conditions supported by the evaluation of welfare markers based on antioxidant status.